Traditional ukulele straps only work through use of strap button. However, most ukuleles are manufactured and sold without a strap button which makes attaching available straps very difficult.
Installing a strap button on your ukulele can damage the instrument, so many people prefer to not do that. Other straps that bypass the use of a button do not provide hands free support.
What is needed is a strap which offers several different methods of strapping a ukulele securely and will allow the user to be hands free.